def wx(self, type = "snow", intensity = 0.5) :
    import osg, osgParticle
    
    try: self.weather
    except:
        self.weather = osgParticle.PrecipitationEffect()
    else :
        self.removeChild(self.weather)
    
    if type == "snow" :
        self.weather.snow(intensity)
    else :
        self.weather.rain(intensity)
    
    self.weather.setFarTransition( self.weather.getNearTransition() / 5 )
    self.addChild(self.weather)
    return self.weather

